patagium

Definitions

from The American Heritage® Dictionary of the English Language, 4th Edition

n. A thin membrane extending between the body and a limb to form a wing or winglike extension, as in bats and flying squirrels.

n. An expandable membranous fold of skin between the wing and body of a bird.

from Wiktionary, Creative Commons Attribution/Share-Alike License

n. The thin membrane that extends between the limbs and body of a bat or of gliding mammals

n. A similar membrane between the body and wing of a bird

from the GNU version of the Collaborative International Dictionary of English

n. In bats, an expansion of the integument uniting the fore limb with the body and extending between the elongated fingers to form the wing; in birds, the similar fold of integument uniting the fore limb with the body.

n. One of a pair of small vesicular organs situated at the bases of the anterior wings of lepidopterous insects. See Illust. of Butterfly.

from The Century Dictionary and Cyclopedia

n. In zoology: The extensible fold of skin of a flying mammal or reptile; the expansion of the integument of the trunk and limbs or tail, or both of these, by which bats, flying-lemurs, flying-squirrels, flying-opossums, and flying-lizards support themselves in the air.

n. The fold of integument which occupies the reëntrant angle between the upper arm and the forearm of a bird, bringing the fore border of the wing to a smooth straightish free edge when the wing is closed. The tensor patagii is a muscle which puts this patagium upon the stretch.

n. In entomology, one of a pair of chitinous scales affixed to the sides of the pronotum of lepidopterous insects, just behind the head, usually covered with long scales or hairs; a shoulder-tippet. Compare tegula.

Examples

Some workers have done this: Charles-Dominique (1977) likened the skin membranes of galagos to incipient patagia, and Feduccia (1993) used the term patagium in connection with sifakas [image above, from Demes et al. (1991), shows the patagia in a sifaka, with the extent of the fur shown in grey around the body].

The way the animal holds its long hindlimbs (referring here to the photo showing the animal from behind) and the suggestion of a patagium now make sense, and the unusual curving shape of the long tail matches the tail posture reported for giant flying squirrels (Meijaard et al. 2006, p. 321) and is unlike that of viverrids and other carnivorans.

On the apparent absence of the patagium in the 'from behind' image (if I may), note that there is, actually, some strange baggy skin on the animal's right side (anterior to its hindlimb), while on the left we can just about make out what appears to be an unusual amount of loose skin extending, along the anterior surface of the left hindlimb, from the ankle toward the belly.

French, from para- as in parasol + chute fall.1:a device for slowing the descent of a person or object through the air that consists of a fabric canopy beneath which the person or object is suspended 2:patagium 3: a device or structure suggestive of a parachute in form, use, or operation.